'The Register' recently announced A bug discovered in the widely used Bash command interpreter poses a
critical security risk to OS X MACs,Unix and Linux systems – and, thanks to their
ubiquity, the internet at large.
It lands countless websites, servers, PCs, OS X Macs, various home routers, and more, in danger of hijacking by hackers.It puts Apache web servers, in particular, at risk of compromise: CGI
scripts that use or invoke Bash in any way – including any child
processes spawned by the scripts – are vulnerable to remote-code
injection. OpenSSH and some DHCP clients are also affected on machines
that use Bash.
The National Vulnerability Database detailed the following issues
-
CVE-2014-6278
Summary: GNU
Bash through 4.3 bash43-026 does not properly parse function definitions
in the values of environment variables, which allows remote attackers
to execute arbitrary commands via a crafted environment, as demonstrated
by vectors involving the ForceCommand feature in OpenSSH sshd, the
mod_cgi and mod_cgid modules in the Apache HTTP Server, scripts executed
by unspecified DHCP clients, and other situations in which setting the
environment occurs across a privilege boundary from Bash execution.
NOTE: this vulnerability exists because of an incomplete fix for
CVE-2014-6271, CVE-2014-7169, and CVE-2014-6277.
Published: 9/30/2014 6:55:04 AM
References
http://www.opencsw.org/packages/CSWbash/
http://tiswww.case.edu/php/chet/bash/bashtop.html
http://www.theregister.co.uk/2014/09/24/bash_shell_vuln/
http://web.nvd.nist.gov/view/vuln/search-results?query=bash&search_type=all&cves=on
http://www.openssh.com/
http://www.isc.org/downloads/software-support-policy/security-advisory/
Consensus opinion on new media at this time: where the system is exposed to such risk (you are using bash shell) update bash to the latest version,download the patched updates when they become available.Mitigate risk with internal,external operational audit and risk assessment.
http://ftp.gnu.org/gnu/bash/bash-4.3-patches/
Using Apache servers
http://security.stackexchange.com/questions/68146/how-do-i-secure-apache-against-the-bash-shellshock-vulnerability
Blogs and websites
http://www.symantec.com/connect/blogs/shellshock-all-you-need-know-about-bash-bug-vulnerability
http://tools.cisco.com/security/center/viewAlert.x?alertId=35845